The early 2000s saw the rapid rise and gradual fall of the pop-up ad. With all current web browsers (even IE) blocking most of them by default, I think it’s safe to finally declare the death of the popup.
Now we just have to endure Snap Preview Anywhere and MyBlogLog Link Tracking hover-overs on every link in your stupid blog.
It’s not helpful. There has never been a time when I’ve idly moved my mouse past a link, gotten bombarded with a slow-loading hover-over widget, and benefited from it. Not once.